Process of finishing textiles with mechanically stable latex of emulsified particles of emulsion-polymerized nonoxidized polyethylene



United States Patent PROCESS OF FINISHTNG TEXTILES WITH ME- CHANICALLY STABLE LATEX 0F EMULSIFIED PARTICLES 0F EMULSION-POLYMERIZED NON. OXIDIZED POLYETHYLENE Fred B. Shippee, East Greenwich, R.I., assignor to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Continuation of application Ser. No. 104,508, Apr. 21, 1961. This application Nov. 20, 1964, Ser. No. 412,828

3 Claims. (Cl. 117-1395) This is a continuation of copending application Serial No. 104,508, filed April 21, 1961, and now abandoned.

This invention relates to a process for treating fibrous materials, and to the products obtained. In particular, the invention relates to methods of treating fibrous materials with certain polyethylene emulsions, and to the products obtained.

Softeners, plasticizers, and lubricants have been used in the art for a number of years as agents to impart certain aesthetic and utilitarian qualities to fibrous materials such as textiles. As used in single additive finishes (self-finishes) for textiles, the softeners are employed to increase the abrasion and wearresistance of fabrics woven from natural and synthetic fibers. The softeners are also employed to improve the handle or softness of fabrics, and to improve their drape and sewing qualities.

Textile softeners, plasticizers, and lubricants have also been employed in the art to modify the properties of textiles treated with thermosetting resins. These thermosetting resins are employed for the crease-proofing, stabilizing, and mechanical finishing of cellulosic textiles.

When used in combination with thermosetting resins, soft-v eners may be added to repair or improve the mechanical properties of the fabric, to produce a particular handle, to reduce the drying or harshness imparted by the thermosetting resins, as simple pocessing aids in reducing friction in high pressure mechanical calendaring or embossing machines, or as an after-treatment to modify resin-treated fabrics that have been improperly finished.

Polyethylene emulsions have heretofore been used as a source of polyethylene as a softening agent in textile treating operations. The use of such emulsions for finishing textiles woven from various fiber materials is discussed, for example, in the American Dyestufi Reporter, May 18, 1959, pages 46-49. Similarly, the use of certain polyethylene emulsions in textile treating processes is disclosed in US. Patent 2,917,412.

- Although the polyethylene emulsions disclosed in the aforementioned article and patent for use in textile treating applications are not described in detail, it is evident, in part from the fact that emulsions containing a polyethylene solids content of as high as 30 percent were employed, that the emulsified polyethylenes are oxidized polyethylenes of the type disclosed in U.S. Patents 2,964,487 and 2,928,797. With the exception of emulsions of these oxidized materials, it is believed that no other stable polyethylene emulsions suitable for use in textile treating applications were available to the art at the time US. Patent 2,917,412 was filed. Indeed, it is believed that no suitable stable. polyethylene latices containing non-oxi-- dized polyethylenes have available to the art up to the present time.

Copending application Serial No. 44,862, filed July 25,

1960, abandoned, and now Serial No. 421,100, filed December 24, 1964, teaches a novel class of nonionically emulsified polyethylene latices produced by an aqueous polymerization process, which latices are unusually stable mechanically and on the shelf, and which can be produced with solids contents upto as high as 30 to 50 percent without adverse effect on stability. The novel'latices disclosed in this copending application are produced in the presence of certain non-ionic emulsifying agents. As disclosed in these co-pending applications, these non-ionic polyethylene latices are prepared by polymerizing ethylene in an aqueous medium at a temperature of about 60- 150 C. preferably at temperatures of C, to C. and at pressures between 2,000-20,000 p.s.i., preferably between about 2500 to 4500 p.s.i. The aqueous medium may contain an alcohol such as t-butanol in amounts of up to 35% by weight of the medium. Using an alkali metal persulphate, such as potassium persulphate, generally in amounts of from 0.08% to 0.50%, polymerization proceeds in the presence of about 1 to 5% of the non-ionic emulsifier, the percentages being based on the weight of aqueous medium. These non-ionic emulsifiers are alkylphenoxy polyoxyethylene glycol emulsifiers of the formula (R=C 11:13.5), etc.

' This copending application discloses in detail the novel polyethylene latices and methods of producing. them. Re-.

production of this detail in the present application is not feasible because of its length, butIit is to be understood. that the teachings of the copending application are in cluded herein by reference.

Similarly, copending application Serial No.104,76 3,;

filed April 21, 19,61, discloses-novel anionically emulsified polyethylene latices produced by an aqueous polymerization process in the presence of emulsifiers such as ('1) salts of saturated fatty acids having 12 to 18 carbon atoms; (2) salts of sulfates of fatty alcohols having about 12 to 18 carbon atoms; and (3) salts of sulfates of ethoxyl- I ated fatty alcohols having 12 to 18 carbon atoms. The

molecular weights of these materials are between 7000 and about 30,00040,000, and the particle size in the latices is between-about 0.02 and 0.5 micron. The latices can be obtained in concentrated solutions containing between 30- 50 percent by weight of solids.

As disclosed in this latter oo-pending application Serial No. 104,763, these latices are produced by polymerizing ethylenein an. aqueous medium at a temperature between about 70 C. to about 100 C. and at pressures of about 2,500 to about at least 5,000 psi. The. aqueous medium,

which may contain up to about 20 to 25 parts by weight of t-butanol, also may contain apH adjuster such as tripotassium phosphate which maintains the pH of the aqueous medium at a value between about 8.5 at 10.5 in the 3 presence of the above enumerated non-ionic emulsifiers. An alkali metal persulphate initiator such as potassium persulphate or sodium persulphate, is employed in concentrations of from about 0.06 to about 0.5 by weight of the aqueous medium.

The details of the latter copending case, since too lengthy for repetition, are similarly incorporated herein by reference.

The polyethylene solids and latices describes in both these copending applications are non-oxidized, substantiallyoxygen-free (less than about 1 percent), polyethylene distinguishable fromthe oxidized polyethylenes known to the prior art for formation of stable dispersions not only by the manner in which they are prepared but by their physical properties.

' Thus, the pro-formed emulsifiable oxidized polyethylene solids of the prior art are limited to relatively low molecular weight materials, up to about 5000. In practice, emulsionsof these materials are not readily prepared in which the polyethylene has a molecular weight of much above 3000. Emulsions formed from the prior art POlYtethylene solids cannot be prepared in a concentration greater than about 25-30 percent by weight of solids. The oxidized polyethylenes, further, have a characteristic disagreeable odor which discourages their use in many applications.

' It has now been found that the polyethylene latices disclosed in the two aforementioned copending patent applications give new and surprising results when employed as treating agents for fibrous materials, including textiles, leather, paper, and the like. In particular, these polyethylene latices have particular utility either as a sole component in a textile treating composition, or in combination with various other textile treating agents including water repellent agents, dye-fixing agents, and thermosetting resins.

These novel polyethylenelatices are compatible with a wide range of textile treating agents, including thermosetting resins and textile catalysts. As adjuncts to a thermosetting resin, their performance is excellent, and is equal to that of typical emulsions of the low molecular weight oxidized polyethylene waxes of the prior art, and superior to these prior art materials in many respects. Thus, crease angle recovery and tear strength enhancement are at least equal to or better than these properties as observed for the prior art oxidized polyethylene substances, so that the life of fabrics treated therewith is increased.

When used as a self-finisher at high concentrations, the novel latices of the copending applications show flex and surface abrasion properties on cotton, rayon, and other synthetics, which properties are superior to those shown by the prior art oxidized polyethylene emulsions, and substantially improve the wear life of fabrics treated therewith.

In addition to lacking the disagreeable odor which is characteristic of the oxidized polyethylenes, the materials of the present invention are uniformly white, have excellent scorch resistance, excellent resistance to accelerated heat aging, and excellent resistance to color change or discoloration due to light exposure. Because of the range of molecular weights in which the novel polyethylene latices of the copending applications can be produced, the hand imparted to a treated fabric can be either firm and full, without stiffness or harshness, or softer, depending on the result desired. The limited range of molecular weights obtainable in the prior art oxidized polyethylenes does not permit a great variation in hand.

In textiles treated with the polyethylene latices of the copending applications, the resulting finish is surprisingly more durable, i.e., will withstand repeated laundering and cleaning without loss of beneficial properties.

It is to be noted that the novel polyethylene latices of the copending applications can be rendered even more desirable for commercial uses by a post-stabilization treatment applied thereto, as disclosed in copending application Serial No. 104,711, filed April 21, 1961. Although this post-stabilization treatment does not materially affeet the characteristic physical properties of the polyethylene solids contained in the latices treated, it renders the latices highly stable, both from the point of view of mechanical stability and shelf stability, and improves the aesthetic quality of the latices by inhibiting the formation of flakes therein, which flakes may be formed by evaporation of surface portions of the latices on storage.

A better understanding of the invention and of its many advantages may be had by referring to the following specific examples, given by way of illustration.

EXAMPLE I A nonionically emulsified stable polyethylene latex was prepared according to Example 1 of copending application Serial No. 44,862. The smooth, white latex obtained from the reactor and having a pH of 2.5 was stripped of t-butanol and concentrated to a final total solids content of 41.8 percent. The pH of the concentrated solution was adjusted to about 7.58.0 by addition of an alkali hydroxide. The particles in the latex had an approximate size between 0.05 to 0.1 micron. The latex was mechanically stable when subjected to 1 minutes agitation in a Waringtype blender at 1700 r.p.m., and was stable to coagulation mercial polyethylene emulsion Moropol 700 (an emul-' sion containing 30 percent solids and having a pH of 8.4:02, and prepared with a commercially available emulsifiable oxidized polyethylene wax.

For purposes of comparison, each of the batches of the novel nonionic latices and the Moropol 700 material were compounded with a resin and an appropriate catalyst to form a pad bath. The resin employed was a commercially available 50 percent aqueous solution of di-' methylol ethylene urea, sold under the trade name Rhonite R-l. As a catalyst, a zinc nitrate type material sold under the trade name Catalyst H-7 was employed.

Five batches (A, B, C, D, and E) of the novel latices were compared with pad baths made up with Moropol 700, and various standard tests were carried out, the results of which are presented in Table I below.

The tests were made on x 80 bleached white cotton print cloth padded at approximately 80 percent wet pickup in treating baths prepared from formulations based on the weight of the total bath. After framing to original dimensions (12 inches by 30 inches), the treated fabric was dried and cured for 5 minutes at 300 F. in an electrically heated circulating air oven.

The testing methods were standard tests as described below:

Warp and filling measurements are reported.

(3) The tear is reported in grams as determined with the Elmendorf tear tester according to Federal Spec.

CCCT-191B: Method 5132.

Warp and filling measurements are reported.

Table I EVALUATION OF FIVE BATOHES OF POLEIHYLENE EMULSION-ORIGINAL TREATMENTS solids was prepared from a nonionic'ally emulsified poly ethylene latex prepared substantially according to Example 1 of copending application Serial No. 44,862.

D. A pad bath containing 0.6 percent polyethylene 5 solids was prepared by proper dilution of the commercial- 5 y u I Pad Bath Composition MCRA Grab Tensile Elmendorflear avallabl? MOFOPOI 700 Fmulslon desmbed camel Strength, lbs. Strength, grams above, wh1ch emuls1on contamed low molecular welght oxidized polyethylene solids. R t }4% Crease resistance angle, grab tensile strength, Elmenm gjjf; 276 43 X 2700) 530 x 270(800) 10 dorf tear strength, and Stoll flex abrasion tests and scorch 2.57 A 292 as x 21(59) 655 X 320(975) c 1972B n 289 35x 24(59) 655x 335(990) resistan e tests were run on cloth samples treated with 1.9%0--- 286 35x22(57) 640x335(975) each of the pad baths descnbed above, and compared 1.97 D 287 34 x 23 57) 655 x 335(990) 1.97; E 282 35x 23(58) 640x 335(975) w1th cloth samples which were untreated. 5.0% Moropol 700 200 35x 10 54 640x 335(975) The results of these measurements are shown 1n Table II below.

Table [1 Percent whiteness Monsanto Stoll Flex Crease Grab Elmendorf Abrasion Pad Bath Recovery Tensile Tear 4/1-W Scorched Angle (Cycles) Treated 4min. 8min.

200 54 x 42 (90) 1,040 x 750 1, 090 82 80 76 19s 53 x 41 (94 1,055 x 750 1, 330 82 79 74 189 55 x 45 (99 1,105 x 720 1, 205 81 70 74 D 1 184 58 x 42 (100 1,170 x 750 1, 000 82 78 73 Untreated- 185 54 x 43 (97) 815 x 545 275 82 80 77 1 Contains oxidized polyethylene solids.

EXAMPLE II The crease angle recovery, Grab tensile, and Elmen- The suitability of anionically and nonionically emulsified stable polyethylene latices, prepared according to the copending applications earlier mentioned herein, as selffinish materials was tested in comparison with the emulsions of the prior art low molecular weight oxidized polyethylene as follows: An 80 x 80 white cotton print cloth of a 4 ounce per yard weight was treated in different pad baths made up with polyethylene latices as later herein defined. Cotton cloth samples were immersed in the bath to an 80 percent wet pickup, framed, dried for five minutes at 250 F., cured for five minutes at 300 F., washed in a household washing machine at 140 F. in the presence of a detergent, and then dried for five minutes at 250 F. The pad baths were made up to contain polyethylene latex samples as described immediately below.

A. A bath containing 0.6 percent polyethylene solids was prepared from an anionically emulsified polyethylene latex as described in Example 5 of copending application Serial No. 104,763. The latex, which contained about percent solids, had :a pH of 6.0 and was emulsified with sodium salts of sulfates of fatty alcohols having about 12-18 carbon atoms, commercially available under the trade name Duponol WAQE.

B. A pad bath containing 0.6 percent polyethylene solids was prepared from an .anionically emulsified polyethylene latex substantially the same as that shown in Example 3 of copending application Serial No. 104,763. The latex contained a total solids content of about 27 percent, had a pH of 10, and was emulsified with potassium stearate. The latex was employed directly as obtained from the reactor, without stripping, and contained about 10 percent butanol.

C. A pad bath containing 0.6 percent polyethylene dorf tear strength are determined as above described. The St-oll flex abrasion test is made according to Fedenal Spec. CCC-T-l9lB: Method 5300, using a Stoll flex abrader at the loading noted.

Fabric whiteness was evaluated with a Photovolt reflection meter equipped with a tri-stimulus blue filter (-Mg0=l00.0). An Atlas scorch tester was used to scorch the treated fabric.

Although specific embodiments have been herein shown and described, it is to 'be understood that they are illustrative, and are not to be interpreted as limiting on the scope and spirit of the invention.

What is claimed is:

1. In the method of finishing textiles with an aqueous polyethylene emulsion, the improvement of contacting said textiles with an aqueous bath comprising a mechanically stable latex of emulsified particles of non-oxidized polyethylene emulsion-polymerized in the presence of (a) a catalyst system and (b) :an emulsifier system with said ethylene containing, by weight, less than about 1% of oxygen, said catalyst system consisting solely of initiators selected from water-soluble alkali metal ei-sulphates, and said emulsifier system consisting solely of emulsifiers selected from the group consisting of (a) alkylphenoxy .polyoxyethylene glycols having the structure wherein R is an alkyl group containing 8 to 9 canbon atoms and where n is an average number of from 7 to 15, (b) salts of saturated fatty acids having 12 to 18 carbon atoms, (c) salts of sulfates of saturated fatty alcohols containing 12 to 18 carbon atoms, and (d) salts of su-lfates of ethoxylated saturated fatty alcohols containing 12-1-8 carbon atoms, said aqueous bath being free of coagulating agents [for said polyethylene particles, and said particles having a size between about 0.02 and 0.6 micron, and then drying and curing the treated textiles. 2. The method as in claim 1 wherein said polyethylene is a self-(finishing agent.

3. The method as in claim 1 wherein said polyethylene is used in combination with a thermosetting resin.

References Cited by the Examiner UNITED STATES PATENTS Seed 26029.6 Hunter 260-296 OFynn et a1.

Reinhardt et a1. 117-139.4 

1. IN THE METHOD OF FINISHING TEXTILES WITH AN AQUEOUS POLYETHYLENE EMULSION, THE IMPROVEMENT OF CONTACTING SAID TEXTILES WITH AN AQUEOUS BATH COMPRISING A MECHANICALLY STABLE LATEX OF EMULSIFIED PARTICLES OF NON-OXIDIZED POLYETHYLENE EMULSION-POLYMERIZED IN THE PRESENCE OF (A) A CATALYST SYSTEM AND (B) AN EMULSIFIER SYSTEM WITH SAID ETHYLENE CONTAINING, BY WEIGHT, LESS THAN ABOUT 1% OF OXYGEN, SAID CATALYST SYSTEM CONSISTING SOLELY OF INITIATORS SELECTED FROM WATER-SOLUBLE ALKALI METAL PERSULPHATES, AND SAID EMULSIFIER SYSTEM CONSISTING SOLELY OF EMULSIFIERS SELECTED FROM THE GROUP CONSISTING OF (A) ALKYLPHENOXY POLYOXYETHYLENE GLYCOLS HAVING THE STRUCTURE 